1. Field of the Invention
This invention relates to systems and methods of building construction and more particularly to systems and methods including a composite of concrete, framing, and other materials and structures.
2. Description of Related Art
Conventional building construction typically comprises three primary systems and methods: (1) wood stud construction; (2) concrete block construction; and (3) concrete panel construction. Wood stud construction system requires skilled carpenters to assemble the pieces and cut lumber according to structural drawings that require skilled interpretation. Concrete block construction, wherein the perimeter of a housing unit is comprised of arranged cinder blocks or concrete blocks in a structurally sound fashion, is slow to put into place and requires a large number of skilled masons to carry out effectively. Concrete panel construction, wherein pre-cast panels are put into place against or in conjunction with a framing system, requires heavy equipment to lift and place the concrete panels, as well as a skilled work force to build the structure that provides the framing template for the panels.
Accordingly, the development of better building systems for constructing low cost, efficient and easily built housing units has been slowed by the need for skilled labor to assemble the components required for the housing unit. In many locales, skilled labor is in short supply and/or prohibitively expensive which has restricted the ability to construct low cost housing units en masse, particularly in underdeveloped countries. Other problems with present building construction technology include the need to build housing units at a low cost and quickly, the ability to build housing units having a resilient construction that does not require a great deal of maintenance, is strong structurally, and provides desired insulation from the elements. Thus, in many countries, the aspirations of having modernized housing units have slowly waned.
Furthermore, present construction methods typically rely on steel stud frames having insulation sprayed or placed on the interior side of the stud wall. Such an arrangement is not as efficient as possible because heat can be conducted from wall surfaces directly to the frame elements, circumventing the surrounding insulation. Providing external insulation, i.e. insulation placed on the outside of the stud frame can be helpful, but to date there has not been a reliable means to applying such insulation. Further, insulation placed only externally will not provide sufficient heat and cold protection and therefore spray or roll insulation will still have to be provided on the inside wall. Thus, the construction can be rendered expensive, cumbersome, and labor intensive.
Several attempts have been made at providing cheaper and more efficient construction methods, however none have adequately address the need for an easier to assemble yet structurally sound and insulative construction. For example, U.S. Pat. No. 4,751,803 to Zimmerman describes a construction method wherein precast concrete studs having protruding fasteners are used to build the framework of the walls of a structure. The walls are assembled in a horizontal plane and rigid sheet insulation is attached to concrete studs and wire mesh is laid upon the sheet insulation. Concrete is then poured onto the insulation, the wire, and the protruding fasteners to form a waterproof outer surface. Beams are bonded to the studs. After construction, the structure can be transported to the construction site and assembled. The patent also discloses a “jig” for assembling the structure. Thus, while providing a means for prefabricating building walls, Zimmerman relies on the use of a jig or form mold in which concrete is poured prior to transportation to the construction site. This severely limits the accessibility of the invention because the relatively heavy poured concrete slabs are expensive and difficult to transport to remote locations, particularly those where affordable housing is desired. Further, the complex stud framing structure renders the system expensive to manufacture and assemble. Finally, the system does not provide for both internal and external insulation of the walls.
U.S. Pat. No. 5,522,194 to Graulich describes a planar building panel core having two faces coated with a cementitious material whereby the core is a closed-cell foam insulation board. A metal grid or lath is laid over the foam before the cement is applied. The core panel includes a plurality of spaced metal furring vertical channel members which are fastened to a support structure and a steel reinforcing sheet spanning the face of each panel, thus comprising a frame surrounding the foam insulation board. Cement is applied over the metal grid and the foam board to result in a unitary construction panel. While providing a relatively sound system, this construction invention is flawed in that there is no means for prefabricating any aspect of the design and it requires extensive assembly of the frame elements around the foam board during construction of the system. Assembly cannot be complete using standard hand tools by unskilled labor. Further, the foam board is not disposed on the exteriors of the frame and therefore the structural rigidity and insulative properties are compromised.
Similarly, U.S. Pat. No. 6,519,904 to Phillips describes a vertical reinforced concrete wall having a plurality of insulating panels horizontally spaced from each other formed of a polystyrene material. A pair of channel-shaped vertical side members are fitted over the respective side edges of the insulating panel during onsite installation. The panels are then mounted between a pair of opposed upper and lower channel-shaped track members which extend horizontally to define the upper and lowers ends of the vertical wall. A wire mesh is attached to the outside of the side members and horizontal members and concrete is applied over the wire mesh, insulation board, and framing members. Again, the complex framing structure is disposed around the foamboard and includes numerous interconnected parts which renders the system difficult to assemble and not amenable to affordable housing construction by unskilled workers. Finally, the construction method does not provide both internal and external insulation at the wall surface.
In contrast, the present invention provides an improved building construction system and method designed to addressed the problems outlined above and provides a systemized product that provides housing for residential or commercial use, can be economically constructed, does not need high level and expensive skilled labor, is extremely strong and weather resistant, has excellent internal and external thermal insulation capabilities, and requires low maintenance. It is, therefore, to the effective resolution of the aforementioned problems and shortcomings of the prior art that the present invention is directed. However, in view of the building construction system and methods in existence at the time of the present invention, it was not obvious to those persons of ordinary skill in the pertinent art as to how the identified needs could be fulfilled in an advantageous manner.